Easy-Implemented Assembly of Monolithic Chalcogenide Thermoelectric Module for Energy Harvesting: Quantifying the Junction Resistance by Co-Optimization of Experiment and Simulation

Generation of electricity from waste heat using thermoelectric devices is one of the best ways to produce the clean energy. Number of applications would become enormous when such devices possess good mechanical strength and high performance in ambient conditions. Here, we design and fabricated such a robust thermoelectric generator (TEGs) using chalcogenide materials in the short time and easy-implemented hot pressing in air. Our typical monolithic π -type device consists of Ag 2 S 0.2 Se 0.8 and Bi 0.5 Sb 1.5 Te 3 for n -type and p -type legs, respectively. The empty space between the legs were filled with highly dense and flexible, thin Ag 2 S working both as insulating spacer and shock absorber, which makes the device very robust and prevents it from any damage due to external mechanical force. The dimension of TEGs device, which is made up with 3 pairs of p - n legs, is 12 mm × 10 mm × 10 mm. From the simulation using COMSOL software, the maximum power density of the device at temperature difference of 50 K were found to be 2.1 and 8.2 mWcm –2 with and without the consideration of the contact resistance at the p - n junction, respectively. Using the novel measurement technique independent of load resistance, the measured maximum power density of the fabricated device was successfully achieved to 2.02 mWcm –2 at room temperature, which confirms the accuracy and wide trial of our measurement technology in obtaining the robust TEG for wide applications.